spritzer

I believe it was either a modified KGSS or a normal BH. I'm sure Kevin will chime in when he can.

What it really needs is a power meter Mac style. Bigger is better here and with enough led's to light up a room.

Ray perhaps...

I could be wrong but they might even be as few as 12.

Yup, it's the indicator light.

Yup. We need something like an oversized GES with better tubes which are also plentiful and cheap. Shall we say a quartet of ECC99's and GU50's for output duty.

The Sigma 11 will work fine on the 252, just remember the polarity.

I replaced the burned up resistor in the 007t with a new one (3 actually in series) but there is still something wrong with the amp. It plays fine but the balance between the output tubes on the left channel is way off as a small change in the pot and I'm up to 300VDC or more with the LED's lit. When it's close to 0V the LED's aren't lit. Btw. Has anybody ever installed 6SA's in a 007t as per KG's instructions? Bingo!! The newer mk2/A is more impressive though as the lower midrange hump is fixed so they seem to have great bass on nearly any amp. Damn... already broke that one...

You better or you might get a visit from the mafia enforcers...

That's the basic thought. Yama's might have put something instead that requires different biasing and is burning up R13. Done deal!! I'm going to see if I can't find the 51K resistors locally and replace them tomorrow. Now I'm off to bed...

That's one option but I don't know where I'd put the massive heatsinks...

I just got the fried SRM-007t we talked about earlier in the thread and it is a sick amp indeed. R13 is burning up and I suspect the diode next to it to be going as well. Yama's has apparently made a brilliant repair attempt and fucked it up. They've also replaced the 2SC3381 bipolar on one side only with some two single units and I'd like to revert it back but the 2SC3381's aren't anywhere to be found, at least not locally. So the question its, does anybody have the schematic for the SRM-007t and know of a similar transistor for the two 2SC3381's?

That's true but the difference shouldn't be all that big since Stax specs all the amps at AC +/-10%.

Transformers are fine if they are of good quality which most aren't. It's also wise to check the output voltage as some output way less then they should. Good to hear that the amp is playing as it should though.

They don't have to be but the Japanese tubes sound great in the Stax amps. The various US made tubes are a clear step back.

I'll leave Al to post his own impressions but the 4070 shows what the SR-404 driver really can do when freed from the craptacular Lambda housing. They were however deigned for a certain job and that is monitoring and that has to be taken into account for any comparisons. I don't think that there is any better tool for the job though as they simply slice the sound up into little bits that can be viewed at will. The bass is controlled and lacks bloom compared to the other Stax models but that allows the most minute of bass detail to spring forth. The midrange isn't as stunning as the one on the SR-007 but it's again very well controlled and the same thing can be said about the treble. It's shares the same slight forward lean of the other Lambda models but it's far cleaner though just a tad shut in. The soundstage is rather limited and that's the only real weakness of the closed design but that's to be expected.

I would at least check the tubes if you have a tester or just replace them. I've never tried NEC branded tubes but I think there were only two manufacturers in Japan and you could get lucky and end up with Toshiba's.

They tend to ease up a bit in the first few hours but there is no K701 10,000hour burn in needed. I really should hook up my 4070 one of these days...

Damn right!!

That's the way to do it. I'm just going to marvel at the crowns in my DAS-R1 instead...

Nice!!! No 1541A S1's??

Happy Birthday!!!

Because being mean makes me feel good...

First off... don't buy from AC. Their prices are nearly as bad as the US retailers so avoid. There are still a few Mk1's floating around new but you are most likely to find them at dealers in the US and Europe then in Japan. It wouldn't hurt to drop a line to EIFL and ask about a Mk1. Welcome to the good forum. There were at least two different versions of the SRD-7 bias supply's but they are all half-way rectified bias doublers with a 100v zener string on the input to limit the voltage. If you Google a voltage doubler it should be there, the only thing Stax did was to connect the - side to the center taps on the transformer and add a 2-5M resistor inline with the + output. That would be the SR-007 you are describing... A new energizer will help and swapping out that "amp" is also a good move for something that works well at low levels.

The going rate was north of 3k$ for the few sets which changed hands so it's definitely not a bad deal.